Google Home will soon show its own panel with Favorite devices on the system’s Device Controls page. The latest update of version 2.65.6.1-dogfood added a new Systemcontrol.panel.GoogleHomePanelAcivity. In the future, when you call the System Device Controls page and select Google Home, you will see precisely this Activity.
You will see all the devices in the favorites tab of the *redesigned* Google Home app. In essence, the added activity copies this tab. You will also be able to edit the list of devices on this page as in the app.